Horizontal Output Circuit And Horizontal Feedback Circuit - Mitsubishi Diamond Pro 750SB Service Manual

3.2.5 Horizontal Output Circuit and Horizontal Feedback Circuit

The horizontal output circuit is composed of the horizontal transistor Q314, the damper diode D317, the
resonance capacitor C332 and the deflection yoke (H_DY).
When the base current fed from the drive circuit is turned ON, a deflection current flows into the horizontal
transistor Q314 for the specified time period. By virtue of the base current drain feature (Ib2), a collector
pulse of about 1000V is generated at the collector of Q314 by the resonance circuit consisting of the
resonance capacitor C332 and H_DY, the linear coil and the "S" capacitor. The pulse width of this resonance
pulse is mainly dependent on the inductance value of the deflection yoke H_DY and the capacitance value of
the resonance capacitor.
Using the collector pulse of this output circuit, the presence of an AFC pulse is detected according to the
capacitance ratio of the resonance capacitor C332 vs. C331 in the AFC feedback circuit. The AFC feedback
circuit is composed of D315, D316, C330, C331, R349, and R350. The detected AFC pulse is DC-rectified by
D315 and C330, and fed back to the +B voltage input circuit (U501: Pin 5 of B_IN) of the oscillator circuit.
(Fig. 3.2.5) Horizontal Output Circuit and Horizontal Feedback Circuit
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